CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   OpenFOAM (http://www.cfd-online.com/Forums/openfoam/)
-   -   probleme of simpleFoam convergence (http://www.cfd-online.com/Forums/openfoam/128897-probleme-simplefoam-convergence.html)

sima_op January 23, 2014 13:30

probleme of simpleFoam convergence
 
5 Attachment(s)
hallo, foamers,
- Introduce of my case:
I'm doing a simulation of incompressible, turbulent flow, two outlets with different pressure, I use inletoutlet boundary condition.For solver i use simpleFoam.
:)There is no problem of my mesh quality, checked by 'checkMesh'.
:)If i close one outlet, it will converge well.
(Here in the attachments is my 'boundary conditions' 'fvScheme' and 'fvSolution'. and my result of calculate)
Problem:
You can see that the 'Initial residual' increase after about '50' iterations. I have no idea about this..
I think it's the problem of settings in 'fvScheme', but i don't know how to deal with it, because i don't understand these schemes at all. If anyone can give me some suggestions...
Thanks very much for your help.:)
Attachment 28212

sima_op January 24, 2014 04:07

is there anyone know why?

alexeym January 24, 2014 04:45

Hi,

As you've only provided fvSchemes and fvSolution, try using PCG instead of GAMG and PBiCG instead of smoothSolver.

Attach solution logs at least if you've got rather secret case files.

sima_op January 24, 2014 05:38

Quote:

Originally Posted by alexeym (Post 471562)
Hi,

As you've only provided fvSchemes and fvSolution, try using PCG instead of GAMG and PBiCG instead of smoothSolver.

Attach solution logs at least if you've got rather secret case files.

Thanks very much for your reply, log file is this: resultat.txt . i just copy some iterations, can you open it?

alexeym January 24, 2014 08:30

Well, you've just shown a log with GAMG and smoothSolver. Still there are lots of possibilities of what's happening. So I can keep guessing or let it go.

1. What are your BCs for turbulence model?
2. What will happen if you remove relaxation?
3. Are you sure there is steady state in the problem?


All times are GMT -4. The time now is 19:49.